You did it right. Cheers

Ok, I have managed to do this with:

awk 'NR == FNR {a[$5];next} $2 in a {print $1} ' file1 file2

If you have any advice please let me know. And sorry for the spam, but i am new in this and really wanted some help :)

Thank you

Actually, I have used the command:

awk 'NR == FNR{a[$5];next} $2 in a' Route_guide_1.txt Carrier_associations_1.txt

but it displays the entire line of file2, and I need only the first sequence.

Thanks

Let's say I have file1 and file2. I want to match a sequence in file1 with a sequence in file2 and return the output with some other sequence from file 2. For example, in file1 I have the line:
Jessica Robert 123 USA association

In file 2 I have:
Mike association UK 567

And I want to return Mike from file2.

Thank you

They are, see eg https://sourceforge.net/p/openvpn/mailman/openvpn-users/, there are already several messages for april 2019.